DE3143128A1 - Method for producing transfer prints by the resist technique - Google Patents

Abstract

A method for producing transfer prints by the resist technique is characterised in that a resist paste is printed onto printed transfer papers, which paste contains a substance (resisting agent) which prevents the sublimation of the colorant situated below the resist paste, no chemical reaction taking place between the resisting agent and the colorant and it being possible for the transfer print to be carried out from the paper to the textile substrate under the generally known conditions. Natural and synthetic polymers, in particular cellulose derivatives, can be used as resisting agent. The printing of the papers with the resist paste can take place by the methods customarily used for printing transfer papers.

Description

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Process for the production of transfer prints according to the reserve technique

With normal textile printing, direct printing, the individual colors are next to each other printed on the substrate. For every single color there is a printing roller or a stencil necessary. The individual printing paste carriers must be carefully matched to one another (reported) so that there are no overlaps (attacks) or unprinted areas (Speed cameras) arise. Very fine patterns, especially geometric figures, lines, points etc. are difficult to manufacture. Sharp contours and true-to-pattern printing without raids and speed cameras can be obtained by printing the colors on top of each other and through Additives ensure that only one color is fixed on the textile material. Achieved this one by the reserve or etching technique.

With the reserve technique in transfer printing, a paste is printed above or below the base color, in which an additive ensures that the basic color does not transfer overprint. This procedure offers 2 advantages:

1. By avoiding robberies and flashes, the pressure loss is much better and more precise, and finer contours can also be created.

2. With the same number of rollers or stencils, there are more patterning options.

The reserve technology for transfer printing is relatively new. There are basically two different ones Options:

Blocking agents in the form of reactant resins or

Blocked by metal ions that are capable of complexing with dyes.

As a reactant resin, for example, hexamethylolmelamine was used in conjunction with a catalyst, e.g., paratoluene sulfonic acid (Litton Business System, US Pat. No. 861422, Dec. 1977).

This reactant resin reacts with suitable dyes before or during the transfer printing process, so that these no longer sublime and can be transferred to the textile material. Other transfer dyes that do not react with the methylol compound can work with the resin

can be printed without blocking the transfer of dye. Be! This type of reserve technique limits the choice of transfer dyes. The second type of reserve technique utilizes the ability of certain transfer dyes to form metal complexes. The formation of metal complexes increases the size of the transfer dye so much that it loses its ability to sublimate and is no longer transferred from the paper to the fiber substrate. Dyes that are not capable of complex formation can sublimate unhindered from the paper onto the textile substrate.

Salts of polyvalent metals such as Fe, Cr, Cd, Al, etc. can serve as complexing agents (Dai Nippon, Japan Patent No. 78/83816 DOS 2,758,398). Copper-amine complexes are particularly suitable.

• Both methods have the disadvantage that the choice of transfer dyes is limited is. The generation of brilliant colors and flawless white effects is also still in preparation Difficulty nagging.

It has now been found that by printing suitable substances on printed transfer paper flawless reserve effects, namely white reserves and colored reserves. These substances act as a barrier layer for the base color or the cover. The method can be used for all sublimable transfer dyes, and not just for certain, as a result Dye types suitable for their chemical constitution, as in the case of the two above methods described is the case.

The barrier effect is achieved by applying film-forming polymers to the transfer paper printed on, which are impermeable to the subliming transfer dyes. Here is one Reaction of the dye with the polymer is not necessary, as in the process with hexamethylolmelamine.

A test of numerous polymers has shown that only very specific substances for the Process are suitable. Polyethylene layers, for example, have no blocking effect at all. Also cellulose-2 1/2 acetates and triacetates, polystyrenes, polyacrylates and polyurethanes show one low locking effect. On the other hand, cellulose ethers, such as e.g. carboxymethyl cellulose, alginates and polysaccharides, such as agar agar, British gum, Gum arabic, guar gum and locust bean gum. Also gelatine and albumins

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show a good blocking effect with higher editions. Carboxymethyl cellulose is particularly effective with a DS of 0.1-1.5.

Above all polymers that have a high glass transition point and also under thermal transfer conditions have a low chain mobility, have a good locking effect. Polymers with a low glass transition point, such as polyethylene, have due to the high chain mobility under thermal transfer conditions a good permeability for sublimating transfer dyes. Between the blocking substances and the dyes no chemical reaction takes place, as is the case with the methods described so far the case is. The sublimation is prevented in a purely physical way. The production the reserve effects are very simple:

A printing paste is printed in places on a printed transfer paper, which has the Substance that prevents sublimation of transfer dyes, e.g. carboxymethyl cellulose. Then it is dried. The reserve paste can be applied using the roller printing process or by the film printing process. A good barrier effect, i.e.

Two good reserve effects are obtained with an application of 5 - 10 g of blocking agent per m.

The blocking agent also acts as a thickener for the printing paste, so that in general no further additives are required. The transfer from paper to textile material takes place in the usual way. The advantages of the method described over the So far known methods are:

1. Applicability for all sublimable transfer dyes.

2. The blocking agent is also a thickening agent, so that it is possible to work with a minimum of additives in the reserve printing paste.

With the new process, not only white reserves, but also colored reserves can be produced will. If you add a sublimable disperse dye to the reserve printing paste, in this way the basic color can be reserved and at the same time the reserved positions print with a different transfer dye. The dye in the reserve printing paste surprisingly, despite the barrier effect of the additive on the base color transferred to the textile material.

Another possible variation is to add a blocking agent to the reserve paste that is not sufficient to completely reserve the base color and, if necessary, to add a further dye to the reserve paste. From the basic color

Then, depending on the amount of blocking agent used, sublimates a more or less large proportion together with the dye in the reserve paste on the textile substrate. In this way, a variety of different color gradations and shades can be achieved .

example 1

The following printing paste, consisting of

75 g Tylose C 30 and 925 g water

is printed on a plain-printed transfer paper using the flat-film printing process and dried at 100 C. The paper treated in this way is applied to PES fabric at 210 C during A thermal transfer print is generated for 30 seconds. You get a very good white reserve with sharp ones Contours.

Example 2

A printing paste is produced, consisting of

80 g CHT alginate NNV and 920 g water.

The printing paste is printed onto a plain transfer paper using the roller printing process printed and dried at 100 C. The transfer to PES knitwear takes place for 30 seconds at 200 ° C. One receives a good white reserve with sharp contours.

Example 3

The following printing paste is produced to generate a color reserve print:

200 g of Tylose C 30 are dissolved in 1700 g of water and 100 g of Resirenbiau TR-WN liquid are added.

The printing paste is printed onto a plain-printed paper using the flat-film printing process and dried at 100 ° C. This is followed by 30 seconds on polyester fabric

reprinted at 210 C. On the yellow background, you get blue patterns with sharp contours without raids and speed cameras.

Claims (9)

Patent claims: 1. A method for producing transfer prints according to the reserve technique, characterized in that a reserve paste is printed on printed transfer paper which contains a substance (reservation agent) which prevents the sublimation of the dye under the reserve paste, with no chemical reaction between the reserve agent and the dye takes place and the transfer from paper to the textile substrate can be carried out under the usual, known conditions. 2. The method according to claim 1, characterized in that the reservation agent is cellulose ether with a degree of substitution of 0.2-1.5, preferably 0.5-1.0, is used. 3. The method according to claim 1 and 2, characterized in that the cellulose ether used is carboxymethyl cellulose with a DS of 0.5-1.0. 4. The method according to claim 1, characterized in that the reservation agent used is alginates used. 5. The method according to claim 1, characterized in that the reservation agent used is polysaccharides, such as British gum, tragacanth, gum arabic or agar agar. 6. The method according to claim 1, characterized in that water-soluble polyamides, such as gelatin, are used as the reservation agent. 7. The method according to claim 1, characterized in that as a reservation center! a combination of the compounds mentioned in claims 1-6 is used. 8. The method according to any one of claims 1-6, characterized in that the reservation agent in Menger
_v Applies transfer paper. curing agent in quantities of 5-10 g / m or a layer thickness of 5-10 jjjn on the ■ .- ^; "v ~" ^ ---- ^: "Ό 1 3H31 ^: 28 9. The method according to any one of claims 1-7, characterized in that one or more sublimable disperse dyes are added to the reserve paste.